1. Field of the Invention
The present invention relates to cranes supported on a tower and, more specifically, to the transfer of the crane from the top of the tower to an adjacent site.
2. Description of the Prior Art
It is known to place a crane on a tower, the top of which is within the reach of a crane on the ground. This tower crane can then be utilized in the construction of a building, or other edifice, adjacent the tower. As the building grows higher, the crane can be used to add sections to the tower on which it is mounted. This has been done, for example, with an elevating, or climbing, mechanism or frame which has a base mounted at selected heights on the tower. The elevating frame has an upper portion which is connected to the crane, and has a ram which, when extended, raises the crane from the top of the tower. When so raised, the crane can lift an additional tower section from the ground and insert the section under the elevated crane. The new section is then connected to the previous upper section of the tower. The ram is then retracted to lower the crane onto the top of the newly added tower section.